no outside network for bridged VM

stanelie

Member
Sep 26, 2014
4
1
23
Hello.

I am unable to get a VM in bridge configuration to access the network outside of the host.

I have one host, with one network card. That card is set up with a static IP. I also set up a bridge on that host, vmbr0
I have one virtual machine. I set it up with one network card, DHCP, in bridge mode connected to vmbr0. This interface receives an IP address from our DHCP server on the same lan as the host. However, the VM is not reacheable from outside the host, and it cannot reach any machine other then the host.

Any ideas what could be wrong?

Here are the config files, I masked the ipv6 addresses :

Host :
root@proxmox1:/etc/apt# cat /etc/network/interfaces
auto lo
iface lo inet loopback
iface eth0 inet manual

auto vmbr0
iface vmbr0 inet static
address 192.168.0.107
netmask 255.255.255.0
gateway 192.168.0.1
bridge_ports eth0
bridge_stp off
bridge_fd 0

root@proxmox1:/# ifconfig
eth0 Link encap:Ethernet HWaddr 00:50:56:9c:c2:f7
inet6 addr: xxxx::xxx:xxxx:xxxx:xxxx/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2281388 errors:0 dropped:0 overruns:0 frame:0
TX packets:1801639 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:472034264 (450.1 MiB) TX bytes:487168628 (464.6 MiB)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:212910 errors:0 dropped:0 overruns:0 frame:0
TX packets:212910 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:93460747 (89.1 MiB) TX bytes:93460747 (89.1 MiB)

tap100i0 Link encap:Ethernet HWaddr 72:5f:47:df:f7:11
inet6 addr: xxxx::xxxx:xxxx:xxxx:xxxx/64 Scope:Link
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:1218 errors:0 dropped:0 overruns:0 frame:0
TX packets:26924 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:74142 (72.4 KiB) TX bytes:2978665 (2.8 MiB)

venet0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
inet6 addr: fe80::1/128 Scope:Link
UP BROADCAST POINTOPOINT RUNNING NOARP MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:3 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

vmbr0 Link encap:Ethernet HWaddr 00:50:56:9c:c2:f7
inet addr:192.168.0.107 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: xxxx::xxx:xxxx:xxxx:xxxx/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2243082 errors:0 dropped:0 overruns:0 frame:0
TX packets:1786671 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:433063058 (413.0 MiB) TX bytes:485574977 (463.0 MiB)

root@proxmox1:/# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 vmbr0
0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 vmbr0

Virtual machine (ubuntu) :

/etc/network/interfaces
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

route -n
root@ubuntu-proxmox:~# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.0.1 0.0.0.0 UG 100 0 0 eth0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0

ifconfig :
root@ubuntu-proxmox:~# ifconfig
eth0 Link encap:Ethernet HWaddr 56:37:b8:09:95:3c
inet addr:192.168.0.125 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: xxxx::xxxx:xxxx:xxxx:xxxx/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:29621 errors:0 dropped:49 overruns:0 frame:0
TX packets:1388 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:3261163 (3.2 MB) TX bytes:88411 (88.4 KB)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:57 errors:0 dropped:0 overruns:0 frame:0
TX packets:57 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:5424 (5.4 KB) TX bytes:5424 (5.4 KB)
 
Found the problem, in case this can be of help to anyone else :

My proxmox server is virtualized under VMware ESXi. I had to go to my VMware host configuration tab, networking, edit the vswitch, go to the security tab and set promiscuous mode to "accept" so that the traffic destined to my VM inside the virtual proxmox server is allowed through the vswitch.

Weird that I still was able to get an IP address from the external DHCP server to my nested VM...

My bad...
 
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